Printed wiring

ABSTRACT

In printed wiring that is formed, on a surface of a base member. by a film of cured electrically conductive ink and that includes: a wavy line; a first wiring element located at one side of both sides sandwiching the wavy line in a width direction; and a second wiring element located at the other side of the both sides and adjacently to the wavy line; a surplus wavy line is provided which is another wavy line, which extends along the wavy line adjacently to the wavy line between the wavy line and the first wiring element, and which is connected to the wavy line to have the same potential.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 16/332,639 filed Mar. 12, 2019, which is a NationalPhase application of International Application No. PCT/JP2017/032985,filed Sep. 13, 2017, which claims the benefit of Japanese PatentApplication Number 2016-201536 filed Oct. 13, 2016, the disclosures ofwhich are expressly incorporated herein by reference in theirentireties.

TECHNICAL FIELD

The present invention relates to printed wiring in which wiring patternsare formed by printing.

BACKGROUND ART

Recently, printing methods, which are superior in terms of productivityand manufacturing costs, have been used for forming electrode patternsor wiring patterns for various types of electronic devices, such astouch panels, touch sensors, membrane switches, and organicelectroluminescence devices. Among these methods, gravure offsetprinting has attracted attention due to its suitability for forminghigh-precision patterns.

Patent Literature 1 describes a case in which a touch sensor is formedby gravure offset printing. FIGS. 1 and 2 show a structure of a touchkey having the touch sensor and a gravure offset printing machine usedfor manufacturing the touch sensor, which are described in PatentLiterature 1.

As shown in FIG. 1, the touch key includes a touch sensor 10 and atouch-sensor driving circuit 15. The touch sensor 10 includes asubstrate 11, net-like electrodes 12 formed on the substrate 11,outer-edge wiring lines 13 provided at outer edges of the net-likeelectrodes 12, and connection wiring lines 14 for connecting theouter-edge wiring lines 13 to the touch-sensor driving circuit 15. Thenet-like electrodes 12 are in the form of meshes. The outer-edge wiringlines 13 extend along the upper sides of the net-like electrodes 12 inFIG. 1.

The net-like electrodes 12, the outer-edge wiring lines 13, and theconnection wiring lines 14 are printed on the substrate 11 at the sametime by using the gravure offset printing machine and are then cured.

As shown in FIG. 2, a gravure offset printing machine 20 includes aplate table 21, a base-member table 22, a doctor blade 23, a transferroller 24, a device frame 25, and a dispenser (not shown). An intaglioplate (gravure plate) 27, where intaglio patterns 26 having a net-likeintaglio portions 26 a, outer-edge intaglio portions 26 b, andconnection intaglio portions 26 c corresponding respectively to thenet-like electrodes 12, the outer-edge wiring lines 13, and theconnection wiring lines 14 of the touch sensor 10 are formed, is placedon the plate table 21 and secured thereto. The substrate 11, which is amember on which printing is performed, is placed on the base-membertable 22 and secured thereto. The doctor blade 23 and the transferroller 24 are both movable along the X-axis and the Z-axis. Thedispenser is also movable along the X-axis and the Z-axis.

While the dispenser supplies electrically conductive paste 28 on theintaglio plate 27, the doctor blade 23 is slid along the X-axis on theintaglio plate 27 to fill the intaglio patterns 26 on the intaglio plate27 with the electrically conductive paste 28. The electricallyconductive paste 28 that fills in the intaglio patterns 26 is receivedby the transfer roller 24, and the printing patterns held by thetransfer roller 24 are transferred to the substrate 11. The printingpatterns transferred to the substrate 11 are cured by heating, thuscompleting the net-like electrodes 12, the outer-edge wiring lines 13,and the connection wiring lines 14 of the touch sensor 10.

PRIOR ART LITERATURE Patent Literature

-   Patent Literature 1: Japanese Patent Application Laid Open No.    2015-45890

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

As described above, Patent Literature 1 describes a case in which wiringpatterns of a touch sensor are formed by gravure offset printing. In thewiring patterns shown in FIG. 1, because wiring elements through whichthe net-like electrodes 12, which are formed as thin-line meshes, areconnected to the connection wiring lines 14 are the line-shapedouter-edge wiring lines 13 and the outer-edge intaglio portions 26 b ofthe intaglio plate 27 corresponding to the outer-edge wiring lines 13are parallel to the doctor blade 23, as shown in FIG. 2, the doctorblade 23 may fall into the outer-edge intaglio portions 26 b duringsqueezing, thus scraping out electrically conductive paste (electricallyconductive ink).

One structure that has been studied to avoid such an inconvenience is astructure in which wiring elements through which the net-like electrodes12 are connected to the connection wiring lines 14 are not theline-shaped outer-edge wiring lines 13 but pads formed of thin-linemeshes made up of line segments that obliquely intersect with the linedirection of the edges (upper sides) of the net-like electrodes 12, thatis, line segments that obliquely intersect with the direction in whichthe doctor blade 23 extends; and, in addition, portions of theconnection wiring lines 14 that extend parallel to the direction inwhich the doctor blade 23 extends are modified to form wavy lines.

The problem of the ink being scraped out, caused by the fall of thedoctor blade into the intaglio portions of the gravure plate, did notoccur in a touch panel which has wiring patterns that included sensorelectrode rows arranged in a sensor area, lead wiring lines for externalconnections, provided at a frame area surrounding the sensor area, andpads through which the sensor electrode rows were connected to the leadwiring lines, where the wiring patterns were formed by using gravureoffset printing according to the foregoing study such that the sensorelectrode rows were made up of first thin-line meshes, the pads weremade up of second thin-line meshes that were denser than the firstthin-line meshes, and further, portions of the lead wiring lines thatextended parallel to the direction in which the doctor blade extendedwere wavy lines; however, a new problem was found in that characteristiclarge blurring caused by remaining ink occurred in the lead wiring linemade up of a wavy line, positioned at downstream areas immediately afterthe wiring elements (pads, electrodes) made up of thin-line meshes inthe squeezing direction. Since the lead wiring lines extending from thesensor electrode rows are placed close to each other in the frame areaof the touch panel, such blurring would cause a severe defect of shortcircuiting of adjacent lead wiring lines.

An object of the present invention is to provide printed wiring that canprevent a short-circuit defect caused by such blurring.

Means to Solve the Problems

Printed wiring according to one aspect of the present invention isformed, on a surface of a base member, by a film of cured electricallyconductive ink, and includes a wavy line, a first wiring element, asecond wiring element, and a surplus wavy line disposed along the a wavyline. The first wiring element is located at one side of both sides inthe width direction of the wavy line. The second wiring element islocated at the other side of the both sides and adjacently to the wavyline. The surplus wavy line is located between the wavy line and thefirst wiring element and adjacently to the wavy line. The surplus wavyline is connected to the wavy line and has the same potential as thewavy line.

Printed wiring according to another aspect of the present invention isformed, on a surface of a base member, by a film of cured electricallyconductive ink, and includes a wavy line, a first wiring element, asecond wiring element, and a surplus wavy line disposed along the wavyline. The first wiring element is located at one side of both sides inthe width direction of the wavy line. The second wiring element islocated at the other side of the both sides and adjacently to the wavyline. The surplus wavy line is located between the wavy line and thefirst wiring element and adjacently to the wavy line. The surplus wavyline is insulated from the wavy line.

Effects of the Invention

According to the present invention, because a surplus wavy line isprovided, even if characteristic blurring occurs at a wavy linedownstream immediately after a first wiring element during squeezingwhen printed wiring is formed, for example, by gravure offset printing,such blurring only occurs at the surplus wavy line. Therefore, ashort-circuit defect caused by blurring can be prevented from occurring,improving the yield.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the configuration of a conventional example ofa touch sensor;

FIG. 2 is a view showing a gravure offset printing machine used tomanufacture the touch sensor shown in FIG. 1;

FIG. 3 is a view illustrating the outline of the structure of a touchpanel;

FIG. 4 is a partial enlarged view showing details of first sensorelectrode rows, pads, and lead wiring lines of the touch panel shown inFIG. 3;

FIG. 5 is a partial enlarged view showing details of second sensorelectrode rows of the touch panel shown in FIG. 3;

FIG. 6 is a partial enlarged view showing details of the lead wiringlines of the touch panel shown in FIG. 3;

FIG. 7A is a view illustrating large blurring that occurs in a leadwiring line made up of a wavy line;

FIG. 7B is a view illustrating a structure that prevents a short-circuitdefect caused by the blurring shown in FIG. 7A from occurring;

FIG. 8 is a partial enlarged view showing printed wiring according to afirst embodiment;

FIG. 9 is a partial enlarged view showing printed wiring according to asecond embodiment;

FIG. 10 is a partial enlarged view showing printed wiring according to athird embodiment;

FIG. 11A is a view showing wiring patterns made up of wavy lines;

FIG. 11B is a view illustrating ink tailing and ink blurring;

FIG. 12A is a view showing a wavy line shape of wiring patternsaccording to a first modification;

FIG. 12B is a view showing a wavy line shape of wiring patternsaccording to a second modification;

FIG. 12C is a view showing a wavy line shape of wiring patternsaccording to a third modification;

FIG. 13A is a view showing the configuration of an example of a gravureplate corresponding to wiring patterns made up of wavy lines; and

FIG. 13B is a view showing the configuration of another example of agravure plate corresponding to wiring patterns made up of wavy lines.

DETAILED DESCRIPTION OF THE EMBODIMENTS

First, a structure of a capacitive touch panel will be described, whichprovided an opportunity for identifying the new problem in which thecharacteristic large blurring caused by the remaining ink occurs in thelead wiring line made up of the wavy line, positioned at downstreamareas immediately after pads and sensor electrode rows made up ofthin-line meshes in the squeezing direction.

FIG. 3 shows the outline of the structure of a capacitive touch panel.In FIG. 3, a transparent substrate is indicated by 30. The capacitivetouch panel has a structure in which a first conductive layer, aninsulating layer, a second conductive layer, and a protective layer, forexample, are sequentially laminated on the transparent substrate 30.

Although not shown in detail in FIG. 3, sensor electrode rows includesfirst sensor electrode rows and second sensor electrode rows. The firstsensor electrode rows are formed by the first conductive layer, and thesecond sensor electrode rows are formed by the second conductive layer,which is insulated from the first conductive layer by the insulatinglayer. In FIG. 3, an area surrounded by a rectangular frame indicates asensor area 40 where the sensor electrode rows are positioned. Theoutside of the rectangular frame is a frame section 50 which surroundsthe sensor area 40.

FIG. 4 shows details of first sensor electrode rows 61, dummy electrodes62, lead wiring lines 63, and pads 64 all formed by the first conductivelayer. FIG. 5 shows details of second sensor electrode rows 71 and dummyelectrodes 72 all formed by the second conductive layer. FIGS. 4 and 5show an upper left part of the sensor area 40 shown in FIG. 3, togetherwith a part of the frame section 50.

In the sensor area 40, the first sensor electrode rows 61 are formedtogether with the dummy electrodes 62, as shown in FIG. 4, and thesecond sensor electrode rows 71 are formed together with the dummyelectrodes 72, as shown in FIG. 5. The dummy electrodes 62 and 72 areformed so as to make the first sensor electrode rows 61 and the secondsensor electrode rows 71 inconspicuous.

The first sensor electrode rows 61, the dummy electrodes 62, the secondsensor electrode rows 71, and the dummy electrodes 72 are formed ofthin-line meshes (first thin-line meshes) which have identicalspecifications and are made up of line segments obliquely intersectingwith the sides of the sensor area 40 that is rectangular. Thin-linemeshes were cut at predetermined portions to form the first sensorelectrode rows 61, insulated from the dummy electrodes 62, and thesecond sensor electrode rows 71, insulated from the dummy electrodes 72.In this example, the unit lattice of the first thin-line meshes has adiamond shape one side of which is 400 μm long, and the line width ofthin lines constituting the meshes is 7 μm. The first sensor electroderows 61 and the dummy electrodes 62 are separated and insulated fromeach other by about 20 μm, as are the second sensor electrode rows 71and the dummy electrodes 72.

The first sensor electrode rows 61 each include island-shaped electrodes61 a arranged along the X direction that is parallel to the long sides41 of the rectangular sensor area 40, and connection sections 61 b thatconnect adjacent island-shaped electrodes 61 a. The first sensorelectrode rows 61 are arranged in rows along the Y direction that isparallel to the short sides 42 of the rectangular sensor area 40. Thesecond sensor electrode rows 71 each include island-shaped electrodes 71a arranged along the Y direction and connection sections 71 b thatconnect adjacent island-shaped electrodes 71 a. The second sensorelectrode rows 71 are arranged in rows along the X direction.

The first sensor electrode rows 61 and the second sensor electrode rows71 intersect with each other in an insulated state. The connectionsections 61 b and 71 b are positioned at positions where the connectionsections 61 b and 71 b overlap each other.

As shown in FIG. 3, lead wiring lines 63 and 73, terminals 81, andground wiring lines 82 are formed in the frame section 50. Pads are alsoformed, which are not shown in FIG. 3. Each of the lead wiring lines 63is drawn, through one of the pads 64 (see FIG. 4), from one of ends onboth sides of the first sensor electrode rows 61 in the X direction.Each of the lead wiring lines 73 is drawn, through one of the pads, fromone of ends on one side of the second sensor electrode rows 71 in the Ydirection. In FIG. 3, among the lead wiring lines 63 and 73 provided forthe frame section 50, only those positioned at both ends are shownwhereas the others are not shown.

The terminals 81 are formed and arranged at a middle portion along onelong side of the rectangular transparent substrate 30. The lead wiringlines 63 and 73 are extended to reach and connect to the terminals 81.The ground wiring lines 82 are formed at a peripheral part of the framesection 50 so as to surround the lead wiring lines 63 and 73. The groundwiring lines 82 are also connected to terminals 81.

The lead wiring lines 73 and the terminals 81 are formed by the firstconductive layer in the same way as the lead wiring lines 63. The groundwiring lines 82 are formed by both the first and second conductivelayers.

The pads 64, through which the first sensor electrode rows 61 areconnected to the lead wiring lines 63, and the pads, not shown, throughwhich the second sensor electrode rows 71 are connected to the leadwiring lines 73 are both formed of thin-line meshes (second thin-linemeshes) made up of line segments obliquely intersecting with the longsides 41 and the short sides 42 of the sensor area 40. The secondthin-line meshes are made to have a higher density than the firstthin-line meshes that constitute the first and second sensor electroderows 61 and 71. In this example, the unit lattice of the secondthin-line meshes is a square having a side length of about 40 μm, andthe line width of the thin lines constituting the meshes is 10 μm.

The terminals 81 and the ground wiring lines 82 are not shown in detail,but are formed of thin-line meshes having a higher density than thefirst thin-line meshes constituting the first and second sensorelectrode rows 61 and 71, in the same way as the pads 64.

On the other hand, the lead wiring lines 63 and 73 are not formed ofmeshes but formed of line-shaped wiring lines. In this example, portionsof the lead wiring lines 63, which are drawn from the pads 64 and extendlong in parallel to the sides 42 of the sensor area 40, that is, alongthe Y direction, are made to be wavy lines, as shown in FIG. 4. In agreat number of lead wiring lines 63 arranged at a lower left part ofthe frame section 50 shown in FIG. 3, FIG. 6 shows portions where anextending direction changes from the Y direction to the X direction.

The first and second conductive layers, having the above-describedstructures, are formed in gravure offset printing by the use ofelectrically conductive ink that includes electrically conductiveparticles, such as silver particles. The squeezing direction S of thedoctor blade with respect to the gravure plate that specifies the wiringpatterns of the conductive layers is the X direction which is parallelto the long sides 41 of the sensor area 40, as shown by an arrow in FIG.3.

As described above, in this example, the wiring patterns other than thelead wiring lines 63 and 73 are formed by thin-line meshes made up ofline segments obliquely intersecting with the squeezing direction S ofthe doctor blade, and among the lead wiring lines 63 and 73, portions ofthe lead wiring lines 63, which extend long along the Y direction (thedirection in which the edge of the doctor blade extends) are wavy lines,thus preventing the problem of the doctor blade falling into theintaglio portions of the gravure plate that specifies the wiringpatterns and scraping out the electrically conductive ink.

On the other hand, as described before, the touch panel having such astructure exhibits a phenomenon whereby characteristic large blurringwas caused by remaining ink in the lead wiring line 63 made up of a wavyline, positioned at downstream areas immediately after the pads 64 madeup of thin-line meshes in the squeezing direction S.

FIG. 7A is an enlarged view of part A in FIG. 4, which shows thisblurring. In FIG. 7A, dotted portions indicate blurring a. Among twolead wiring lines 63, only one lead wiring line 63 positioned upstreamin the squeezing direction S caused blurring a, but the other leadwiring line 63 positioned downstream did not cause blurring a. Theblurring a caused the two adjacent lead wiring lines 63 to have a shortcircuit, as shown in FIG. 7A.

Characteristic blurring a like that shown in FIG. 7A has the followingtwo characteristics.

(1) Blurring occurs only when a wiring element that causes a relativelylarge frictional resistance against the doctor blade is positionedrelatively close upstream of the squeezing, with respect to the wavyline traversing the squeezing direction.

(2) Even when parallel wavy lines are provided downstream of a wiringelement that causes a relatively large frictional resistance, blurringoccurs only at one wavy line positioned on the most upstream side.

Here, “relatively close upstream of” is specified because it wasobserved that blurring a was not easy to occur when the distance betweena wavy line and a wiring element positioned upstream was long, and it isinferred that blurring a would not occur if a sufficiently-wide, flatportion exists between the wavy line and the wiring element in thegravure plate.

On the basis of the fact that only the pads 64 and electrodes (the firstsensor electrode rows 61 and the dummy electrodes 62) formed ofthin-line meshes were wiring elements positioned upstream when suchblurring a actually occurred, the inventor inferentially generalized thepads 64 and the electrodes formed of thin-line meshes to provide thedefinition of “a wiring element that causes a relatively largefrictional resistance against the doctor blade”.

It could be considered that, if dense unevenness that causes arelatively large frictional resistance against the doctor blade existson the gravure plate, the edge of the doctor blade that passes the denseunevenness is lifted slightly from the surface of the gravure plate,causing this blurring a. However, the reason why only one wavy linelocated on the most upstream side causes this blurring a has not beenfound at this time.

When a wiring element such as a wavy line exists in the vicinity,downstream in the squeezing direction, of a wavy line that caused suchblurring a, the wiring element and the wavy line cause short-circuiting,which causes a severe defect. This short-circuiting is indicated by twolead wiring lines 63 made up of wavy lines shown in FIG. 7A.

To avoid the occurrence of a short-circuiting defect caused by suchblurring a, taking into consideration the above-describedcharacteristics (1) and (2), another wavy line is provided as a surpluswavy line in the present embodiment, the surplus wavy line beingadjacent to a wavy line and extends along the wavy line upstream in thesqueezing direction of the wavy line, in other words, at the side wherethe first wiring elements are positioned, with respect to the wavy linesandwiched by first wiring elements that cause slight lifting (floatingup) of the doctor blade and a second wiring element with whichshort-circuiting may occur. With this, blurring a may occur only at thesurplus wavy line, and blurring a that causes a short-circuit with thesecond wiring element is prevented from occurring at the wavy line.

FIG. 7B shows a state in which a surplus wavy line 91 is provided, incontrast with the structure shown in FIG. 7A, and blurring a occurs atthe surplus wavy line 91. It is assumed here that the surplus wavy line91 does no cause any electrical problem even if blurring a causes ashort-circuit between the surplus wavy line 91 and a lead wiring line63.

FIG. 8 shows a specific structure in which surplus wavy lines 91 areprovided for the touch panel described before. FIG. 7B corresponds to aportion A in FIG. 8.

Each pad 64 includes a straight part 64 a that goes along with a sideedge of the first sensor electrode row 61 and a protruding part 64 bthat protrudes from the straight part 64 a in the outer-edge directionof the frame section 50 and that connects to the lead wiring line 63. Inthis example, as shown in FIG. 8, a surplus wavy line 91 extends alongand adjacent to the lead wiring line 63 between the protruding sections64 b of the pad 64 and an adjacent pad 64, upstream of the lead wiringline 63 in the squeezing direction S.

In this example, each surplus wavy line 91 is connected to theprotruding part 64 b of the pad at one end (at the upper end) and isconnected to the lead wiring line 63 at the other end. The surplus wavyline 91 is connected to the lead wiring line 63 in parallel.

Since the above-described structure is employed, characteristic blurringa may occur at the surplus wavy line 91. Even if the surplus wavy line91 is short-circuited with the adjacent lead wiring line 63 due toblurring a, because the lead wiring line 63 is connected in parallel toand has the same potential as the surplus wavy line 91, no electricalproblem occurs.

Since the lead wiring line 63 drawn from the uppermost pad 64 does nothave any second wiring element with which a short-circuit may occur,there is no need to provide a surplus wavy line 91. If a detectioncircuit for a touch panel having no surplus wavy line 91 is used as adetection circuit for the present touch panel, since it is necessary tomaintain differences among the resistance of a great number of leadwiring lines 63 (reason 1), a surplus wavy line 91 is provided for theuppermost pad 64.

In this example, as described before, each of the lead wiring lines 63is drawn, through one of the pads 64, from one of ends on both sides ofthe first sensor electrode rows 61 in the X direction. Since the leadwiring lines 63 located at the opposite side in the X direction to thatshown in FIG. 8 are positioned upstream of the pads 64 in the squeezingdirection S, blurring a does not occur and no problem exists. However,it is desirable that the touch panel be symmetric in all electriccharacteristics such as resistance and capacitance (reason 2), andtherefore, the same surplus wavy lines are provided symmetrically withrespect to the lead wiring lines 63 located at the opposite side in theX direction (details are not shown).

In FIG. 8, the surplus wavy lines 91 are connected in parallel to thelead wiring lines 63. However, it is not necessarily required to havesuch a configuration. FIG. 9 and FIG. 10 show other configurations. InFIG. 9, unlike the surplus wavy lines 91 shown in FIG. 8, surplus wavylines 91′ are not connected to pads 64 at ends (upper ends) but areconnected to the lead wiring lines 63 at the other ends. In FIG. 10,surplus wavy lines 91″ are unconnected to the pads 64 and the leadwiring lines 63 at respective ends, being insulated from the lead wiringlines 63.

The surplus wavy lines can be those shown in FIG. 9 or FIG. 10. When thesurplus wavy lines 91′ shown in FIG. 9 or the surplus wavy lines 91″shown in FIG. 10 are used, it is not necessary to take intoconsideration the above-described reasons 1 and 2. Therefore, thesurplus wavy line 91′ or 91″ provided for the lead wiring line 63 drawnfrom the uppermost pad 64 in FIG. 9 or FIG. 10 could be omitted. Inaddition, a surplus wavy line 91′ or 91″ may also be omitted for thelead wiring line 63 located at the other side in the X direction.

Printed wiring according to the present embodiment has been describedabove by using wiring patterns in the first conductive layer of thetouch panel as an example. The present embodiment relates to printedwiring that is formed, on a surface of a base member, by a film of curedelectrically conductive ink and that, at least, includes one wavy line;first wiring elements located at one of both sides sandwiching the wavyline in the width direction; and a second wiring element located at theother side of both sides and adjacently to the wavy line, and ischaracterized by providing one more wavy line (a surplus wavy line) thatextends along the wavy line and adjacent to the wavy line between thewavy line and the first wiring elements.

Wiring elements here mean the structural elements of wiring made up ofconductors, such as wiring lines, electrodes, pads, and portionsthereof. In the structures of the touch panels shown in FIGS. 8 to 10, apad 64 made up of highly dense thin-line meshes corresponds to the firstwiring element; and, with respect to a lead wiring line 63 for which asurplus wavy line 91 (91′ or 91″) is adjacently provided, a lead wiringline 63 (another wavy line) located adjacent thereto and also located atthe opposite side to the surplus wavy line 91 (91′ or 91″) correspondsto the second wiring element. Here, “adjacent to” means that anotherwiring element is not positioned therebetween.

Wavy-line shapes applied to wavy-line wiring patterns, such as thesurplus wavy lines 91, which extend long in the Y direction of the leadwiring lines 63 (in the direction in which the edge of the doctor bladeextends), will be described next.

Wavy-line patterns 100 forming wavy lines shown in FIG. 11A are formedof triangular waves.

When wavy lines of the wavy-line patterns forming wavy lines are formedof triangular waves, as shown in FIG. 11A, printed wiring patterns 100tend to have problematic shapes as shown in FIG. 11B. Specifically,tailing of electrically conductive ink may occur at bending portions(zigzag portions) of the triangular waves located downstream in thesqueezing direction S, as indicated by “b”, and blurring of electricallyconductive ink may occur at bending portions of the triangular waves, asindicated by “c”.

If such tailing b or blurring c of the electrically conductive inkincreases, the electrically conductive ink may contact an adjacentwiring pattern, causing a short-circuit defect. This prevents thearrangement pitch of wiring patterns from being made smaller.

In the wavy lines forming wiring patterns 110, 120, and 130 shown inFIGS. 12A to 12C, the apexes of the bending portions of triangularwaves, located downstream in the squeezing direction S and protruding inthe direction perpendicular to the direction in which the triangularwaves extend, are cut in order to reduce the degree of risk that theabove-described tailing b or blurring c contacts an adjacent wiringpattern.

The wiring patterns 110 shown in FIG. 12A are cut at bending portions toform V-shaped notches 111. The wiring patterns 120 shown in FIG. 12B arecut straight at bending portions to form truncated portions 121. Thewiring patterns 130 shown in FIG. 12C are cut at bending portions toform W-shaped notches 131. Providing such cut portions reduces thedegree of risk of ink tailing b or blurring c contacting an adjacentwiring pattern, even if the tailing b or blurring c occurs, because thedimensions thereof are small, allowing the arrangement pitch of thewiring patterns to be made smaller. It is noted here that, in the wiringpatterns 110, 120, and 130 shown in FIGS. 12A to 12C, the bendingportions protruding in the opposite direction to those where the cutportions 111, 121, and 131 are formed are cut straight to form cutportions 112, 122, and 132.

To prevent such tailing b or blurring c, it is also effective to formrelievo portions 202 at intaglio portions 201 in a gravure plate 200corresponding to the wavy-line wiring patterns 100 to reduce the amountof electrically conductive ink used, as shown in FIG. 13A. With this, asa result, vacant spaces (spaces without film) or pits in the film,corresponding to the relievo portions 202 in the gravure plate 200, areformed in the wavy-line wiring patterns 100. It is preferred that therelievo portions 202 be formed at the bending portions of wavy lines. Itis further preferred that the relievo portions 202 be formed with ashift in the squeezing direction S, as shown in FIG. 13B. One pit in thefilm or one space without film is formed in the width direction of thewavy-line shape and one or more thereof is formed in the longitudinaldirection.

The line-shaped lead wiring lines 63 and 73 in the touch panelsdescribed before are made up of wiring lines thicker than the thin linesconstituting thin-line meshes in order to reduce the resistance and toavoid wiring disconnection risk. Therefore, printing defects easilyoccur due to electrically conductive ink left on the blanket in gravureoffset printing. Forming the relievo portions 202 at the intaglioportions 201 in the gravure plate 200 is preferred also for preventingsuch printing defects. In terms of this point, it is preferred thatrelievo portions be formed at intaglio portions in the gravure plate,corresponding not only to the wavy-line portions of the wiring patternsbut also to the straight portions thereof.

What is claimed is:
 1. A printed wiring formed on a surface of a basemember by a film of cured electrically-conductive ink, the printedwiring comprising: a first wavy line; a first wiring element; a secondwavy line disposed along the first wavy line, wherein: an apex of abending portion included in the second wavy line has a flatconfiguration, the bending portion protruding in a width direction ofthe second wavy line, and the bending portion that has the flatconfiguration being located at at least one of both sides in the widthdirection of the second wavy line; and inside the second wavy line, onepit or one space is disposed in a width direction of a wavy-line shapeand one or more pits or one or more spaces are disposed in alongitudinal direction of the wavy-line shape; and a surplus wavy linedisposed along the first wavy line, the first wiring element beinglocated at one side of both sides in a width direction of the first wavyline, the second wavy line being located at the other side of the bothsides and adjacent to the first wavy line, wherein the surplus wavy lineis: located between the first wavy line and the first wiring element,and adjacent to the first wavy line, separated by a distance from thefirst wiring element in the width direction of the first wavy line, andconnected to the first wavy line and has a same potential as the firstwavy line.
 2. The printed wiring according to claim 1, wherein the firstwiring element is an electrode made up of thin-line meshes or a wiringline made up of thin-line meshes.
 3. The printed wiring according toclaim 1, wherein an apex of a bending portion included in at least oneof the first wavy line and the surplus wavy line has a flatconfiguration, the bending portion protruding in a width direction ofthe at least one of the first wavy line and the surplus wavy line, andthe bending portion that has the flat configuration being located at atleast one of both sides in the width direction of the at least one ofthe first wavy line and the surplus wavy line.
 4. The printed wiringaccording to claim 1, wherein, inside at least one of the first wavyline and the surplus wavy line, one pit or one space is disposed in awidth direction of a wavy-line shape and one or more pits or one or morespaces are disposed in a longitudinal direction of the wavy-line shape.5. A printed wiring formed on a surface of a base member by a film ofcured electrically-conductive ink, the printed wiring comprising: afirst wavy line; a first wiring element; a second wavy line disposedalong the first wavy line, wherein: an apex of a bending portionincluded in the second wavy line has a flat configuration, the bendingportion protruding in a width direction of the second wavy line, and thebending portion that has the flat configuration being located at atleast one of both sides in the width direction of the second wavy line;and inside the second wavy line, one pit or one space is disposed in awidth direction of a wavy-line shape and one or more pits or one or morespaces are disposed in a longitudinal direction of the wavy-line shape;and a surplus wavy line disposed along the first wavy line, the firstwiring element being located at one side of both sides in a widthdirection of the first wavy line, the second wavy line being located atthe other side of the both sides and adjacent to the first wavy line,wherein the surplus wavy line is: located between the first wavy lineand the first wiring element, and adjacent to the first wavy line,separated by a distance from the first wiring element in the widthdirection of the first wavy line, and insulated from the first wavyline.
 6. The printed wiring according to claim 5, wherein the firstwiring element is an electrode made up of thin-line meshes or a wiringline made up of thin-line meshes.
 7. The printed wiring according toclaim 5, wherein an apex of a bending portion included in at least oneof the first wavy line and the surplus wavy line has a flatconfiguration, the bending portion protruding in a width direction ofthe at least one of the first wavy line and the surplus wavy line, andthe bending portion-that has the flat configuration being located at atleast one of both sides in the width direction of the at least one ofthe first wavy line and the surplus wavy line.
 8. The printed wiringaccording to claim 5, wherein, inside at least one of the first wavyline and the surplus wavy line, one pit or one space is disposed in awidth direction of a wavy-line shape and one or more pits or one or morespaces are disposed in a longitudinal direction of the wavy-line shape.9. An electronic device comprising: a base; and a printed wiringprovided on a surface of the base, the printed wiring being formed by afilm of cured electrically-conductive ink, wherein the printed wiringcomprises: a first wavy line; a first wiring element; a second wavy linedisposed along the first wavy line, wherein: an apex of a bendingportion included in the second wavy line has a flat configuration, thebending portion protruding in a width direction of the second wavy line,and the bending portion that has the flat configuration being located atat least one of both sides in the width direction of the second wavyline; and inside the second wavy line, one pit or one space is disposedin a width direction of a wavy-line shape and one or more pits or one ormore spaces are disposed in a longitudinal direction of the wavy-lineshape; and a surplus wavy line disposed along the first wavy line, thefirst wiring element being located at one side of both sides in a widthdirection of the first wavy line, the second wavy line being located atthe other side of the both sides and adjacent to the first wavy line,wherein the surplus wavy line is: located between the first wavy lineand the first wiring element, and adjacent to the first wavy line,separated by a distance from the first wiring element in the widthdirection of the first wavy line, and connected to the first wavy lineand has a same potential as the first wavy line.
 10. An electronicdevice comprising: a base; and a printed wiring provided on a surface ofthe base, the printed wiring being formed by a film of curedelectrically-conductive ink, wherein the printed wiring comprises: afirst wavy line; a first wiring element; a second wavy line disposedalong the first wavy line, wherein: an apex of a bending portionincluded in the second wavy line has a flat configuration, the bendingportion protruding in a width direction of the second wavy line, and thebending portion that has the flat configuration being located at atleast one of both sides in the width direction of the second wavy line;and inside the second wavy line, one pit or one space is disposed in awidth direction of a wavy-line shape and one or more pits or one or morespaces are disposed in a longitudinal direction of the wavy-line shape;and a surplus wavy line disposed along the first wavy line, the firstwiring element being located at one side of both sides in a widthdirection of the first wavy line, the second wavy line being located atthe other side of the both sides and adjacent to the first wavy line,wherein the surplus wavy line is: located between the first wavy lineand the first wiring element, and adjacent to the first wavy line,separated by a distance from the first wiring element in the widthdirection of the first wavy line, and insulated from the first wavyline.